Wrist brace

ABSTRACT

The invention relates to an aid for relaxing the extensor musculature in the forearm. The invention also relates to a method for relaxing the extensor musculature in the forearm. The aid and the method mentioned according to the invention are both based on the principle of the flexor-extensor antagonism and can be used for physiologically relaxing an extensor musculature.

BACKGROUND OF THE INVENTION

[0001] The invention relates to an aid for relaxing the extensormusculature in the forearm.

[0002] The invention also relates to a method for relaxing the extensormusculature in the forearm.

SUMMARY OF THE INVENTION

[0003] The aid and method according to the invention are both based onthe principle of the flexor-extensor antagonism and can be used forphysiologically relaxing an extensor musculature. This extensormusculature is an extensor muscle, i.e. an extensor in the forearm whichis connected to the lateral epicondyle. The extensor musculature is inantagonistic action with the flexor musculature.

[0004] The object of the invention is to relax the extensor musculaturein the forearm. To this end, an aid according to the invention ischaracterized in that it is provided with a first body, a second bodyand at least one hinge joint hinging the first and the second bodytogether, the first body being arranged to be secured to a forearm whilethe second body extends from the hinge to a palm of the hand belongingto the forearm, the aid being further provided with resilient meanswhich, in use, generate a moment of force between the first and secondbody such that the second body, hinging relative to the first body,presses against the palm of the hand in a direction directed towards theupper side of the hand belonging to the palm. In the forearm to whichthe aid is secured, a wearer of the above-mentioned aid will experiencea moment of force equivalent to a moment of force which is created byflexing the extensor musculature. As a result, the flexor musculaturewill be flexed. The extensor musculature is thereby physiologicallyrelaxed. Relaxation of the extensor musculature is one of the possibleapplications of the invention which can be of interest in the case ofinjured extensor musculature. An example of an injured extensormusculature is a so-called tennis elbow. Such as injury occursfrequently. This injury results in pain stimuli coming from the originof the extensor musculature at the elbow. This origin is the epicondyle.Physiological relaxation of the extensor musculature reduces the painstimuli and promotes recovery of the injury. Heretofore, in case of aninjury to the extensor musculature, use is made of straps being tiedaround the forearm. Although these straps provide some support to theextensor musculature, the extensor musculature is thereby hardlyrelaxed, if at all.

[0005] Preferably, the first body is provided with a firstchannel-shaped member of a rigid material. In particular, the firstchannel-shaped member is arranged to embrace, in use, at least a part ofan underside of the forearm. It has been found that with this variant,attachment to the forearm is best to generate the desired moment offorce.

[0006] Further, it is preferred that the second body is provided with asecond channel-shaped member of a rigid material.

[0007] In particular, the second channel-shaped member is arranged toabut, during use, against at least a part of an inside of the handsituated between the index finger and the little finger.

[0008] According to a highly advanced embodiment of the aid according tothe invention, the first channel-shaped member is provided with a firstand second side wall situated opposite each other, the secondchannel-shaped member is provided with a first and second side wallsituated opposite each other, and the at least one hinge comprises afirst and second hinge, the first hinge hinging the first side wallstogether around a rotation axis and the second hinge hinging the secondside walls together around the rotation axis. It has been found thatsuch an aid can be very easily worn without the user suffering muchhindrance. Also, it is hardly, if at all, visible that the user iswearing the aid. Moreover, clothing can be worn in the normal manner.

[0009] In particular, the first hinge is provided with a first metalresilient bar-shaped member having a first and second end which areconnected to the first side walls of the first and second channel-shapedmember, respectively, and the second hinge is provided with a secondmetal resilient bar-shaped member having a first and second endconnected to the second side walls of the first and secondchannel-shaped member, respectively, the first and second bar-shapedmembers forming the resilient means.

[0010] A particular advantage of this embodiment is that the hinges canwork, without friction and noise.

[0011] Due to the resilient means and the hinge being integrated in thefirst and second metal, flexible bar-shaped member, the aid can bedesigned to be very compact, which, again, offers great advantages for auser when wearing the aid.

[0012] According to a highly advanced embodiment, the resilient meansare provided with memory metal. Such a material has a number of veryspecial properties. For instance, large elastic deformation is possible.Further, the material comprises a very low rigidity modulus when thematerial stress reaches the so-called plateau stress. Such anarrangement has the advantage that with a selected initial moment offorce in a particular position of the hand relative to the arm, themoment of force will change only slightly with an increasing ordecreasing angle of bend. This is caused by the relatively low springconstant. As a result of all this, a substantially constant flexiforce,that is, moment of force is exerted on the hand, independently of theposition the hand takes around the wrist joint relative to the forearm.

[0013] In particular, the first and second bar-shaped member aremanufactured from, the memory metal.

[0014] Preferably, the memory metal comprises a memory alloy inaustenitic condition. As a result of all this, the first and the secondbar-shaped member can have a length varying between 40 mm and 120 mm.The first and the second bar-shaped member can have a diameter of 0.5 mmto 2 mm. Further, the above-mentioned advantage of the substantiallyconstant moment of force is present.

[0015] A favorable embodiment of the aid according to the invention ischaracterized in that the first body is substantially tubular and isprovided with a channel-shaped member of a rigid material, and a firstelastically adjustable strap connected to the channel-shaped member, thechannel-shaped member being arranged to embrace, in use, at least a partof an upper side of the forearm while the first strap bridges an openlongitudinal-side of the channel-shaped-member, thereby passing over atleast a part of the underside of the forearm. With the first,elastically adjustable strap, provided to that end with, for instance, aVelcro tape closure or clasps, the first body can be secured to theforearm. The second body of the aid should be connected to the hand ofthe forearm. To this end, a further elaborated embodiment according tothe invention is characterized in that the second body is arranged toembrace the part of the hand situated between the fingers and the thumb.Preferably, the hand is then only party covered, so that it can continueto perform its gripping functions substantially completely. In a specialembodiment, the aid is further characterized in that the second body hasa substantially tubular design and is manufactured from a rigidmaterial.

[0016] An advantageous embodiment of the aid according to the inventionis characterized in that the resilient means are provided with aresilient body having a first and second end between which, when theyare moved further away from each other, a spring force increases, afirst end being connected to the first body at a position which, in use,lies at an upper side of the forearm and the second end being connectedto the second body at a position which, in use, is situated at an upperside of the hand. The resilient body applies a moment of force betweenthe first and the second body, allowing the second body to hingerelative to the first body about the hinge situated between the twolatter bodies. A particularly advantageous embodiment according to theinvention is characterized in that the first body is provided with afirst and second side wall situated opposite each other, the second bodyis provided with a first and second side wall situated apposite eachother and the at least one hinge comprises a first and second hinge, thefirst hinge hinging the first side walls together around a rotation axisand the second hinging the second side walls together around therotation axis. In a particular embodiment, the aid is furthercharacterized in that the first and second hinge are each provided withthe resilient means which press the first and second body relative toeach other about the rotation axis to a predetermined position in whichthe first and second body include a predetermined angle, which angle isin a plane directed perpendicularly to the rotation axis.

[0017] The invention also provides a method for relaxing the extensormusculature through the principle of the flexor-extensor antagonism,wherein, by the exertion of forces on at least three pressure points ona forearm, the wrist of the forearm and the palm of the hand of theforearm, respectively, a moment of force is applied to the palm of thehand, such that the flexor musculature in the forearm must be flexed, asa result of which, due to the antagonism between the flexor musculatureand the extensor musculature in the forearm, the extensor musculature isrelaxed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention will presently be further elucidated with referenceto the drawing. In the drawing:

[0019]FIG. 1 schematically shows the principle of the invention forrelaxing the extensor musculature by using at least three pressurepoints;

[0020]FIG. 2a shows a schematic overview of relevant forces and momentsof force in the forearm without external force;

[0021]FIG. 2b shows a schematic overview of relevant forces and momentsof force in the forearm with an external force of an aid according tothe invention;

[0022]FIG. 3a schematically shows a side view of a first possiblepractical embodiment of an aid according to the invention;

[0023]FIG. 3b shows a perspective representation of the aid according toFIG. 3a;

[0024]FIG. 4 shows a first alternative embodiment of the aid accordingto the invention;

[0025]FIG. 5 shows a second alternative embodiment of the aid accordingto the invention;

[0026]FIG. 6a shows a third alternative embodiment of the aid accordingto the invention in a condition in which it is worn; and

[0027]FIG. 6b shows the aid of FIG. 6a in a relaxed condition when, itis not worn.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0028]FIG. 1 shows a forearm 2 on which three pressure points 4, 6 and 8are indicated. The first pressure point 4 is located on the underside ofthe forearm, the second pressure point 6 is located on the wrist of theforearm and the third pressure point 8 lies against the palm of the handof the hand 10. By applying forces to these at least three pressurepoints, a force component F_(aid) 12 is applied to the palm of the hand,such that the hand 10 is pressed in a direction towards the upper sideof the hand belonging to the palm of the hand. This is furtherelucidated in FIG. 3a. In FIG. 3a, an aid 13 is shown which is securedto a forearm 2. The flexor musculature 14 (flexor muscle) is a flexorwhich is in antagonistic action with the extensor musculature 16. Theextensor musculature 16 (extensor muscle) is an extensor which isconnected to the lateral epicondyle 17 in the elbow. The force componentF_(aid) 12 has as a result that flexor musculature 14 in the forearm 2has to be flexed. As a result of the antagonistic action, which will befurther elucidated below, the extensor musculature 16 will bephysiologically relaxed. This relaxation is particularly important incase the extensor musculature is injured. A common injury of theextensor musculature is the so-called “tennis elbow”. This injuryresults in pain stimuli which come from the origin of the extensormusculature in the elbow (epicondyle) 17. The physiological relaxationof the extensor Musculature according to the invention promotesrecovery.

[0029]FIGS. 2a and 2 b give a schematic overview of relevant forces andmoments of force in the forearm 2. In FIG. 2a, no external force isincorporated. FIG. 2b does involve an external force, which is exerted,for instance, by an aid according to the invention.

[0030]FIG. 2a is a schematic overview of a forearm 2 with an associatedhand 10. It is schematically indicated how a force F_(ext) 18 is exertedby the extensor musculature, and a force F_(flex) 20 is exerted by theflexor musculature on the hand 10. There are no external forces workingon the forearm. The force F_(ext) 18 yields a force component, F_(ext) ⊥122 perpendicular to the hand 10 relative to the wrist joint 24, whichmakes the hand 10 hinge in the direction of rotation R. The force Flex20 yields a force component F_(ext) ⊥ 26 perpendicular to the hand 10,relative to the wrist joint 24, which makes the hand 10 hinge in adirection opposite to the direction of rotation R. FIG. 2b shows theresult of the application of an external force component F_(aid) 12 tothe hand 10 (this force component is, for instance, generated by an aidaccording to the invention). To control the hand 10, there must almostbe a near balance of moments of force relative to the joint 24. Whatapplies here is that the flexor musculature should apply a moment offorce (F_(flex), ™*R₁₄) 26 which is almost equal to but opposite to thesum of the moments of force (F_(ext), ⊥*R₂) 22 and (F_(aid)*R₃) 12.(Wherein R₁, R₂ and R₃ are the respective arms of the force componentsF_(flex), ⊥, F_(ext), ⊥ and F_(aid), relative to the wrist joint 24).From the foregoing, it follows that the force component F_(ext) 22generated by the extensor musculature will be smaller than in the casewhere the force component F_(aid) 12 is not presented. The force F_(ext)18 which is exerted by the extensor musculature will also be smaller. Inthis way, the extensor musculature is physiologically relaxed throughthe flexor-extensor antagonism.

[0031]FIG. 3a shows the forearm 2 to which a possible practicalembodiment of an aid 13 according to the invention is secured. The aid13 for relaxing the extensor musculature 16 in the forearm is providedwith a first body 30 and a second body 32. The aid further comprises atleast one hinge joint 34 which hingedly connects the first aid secondbody. In this example, two hinges are involved. The first body 30 isarranged to be secured to a forearm 2 while the second body 32 extendsfrom the hinge 34 to a palm of the hand 36 belonging to the forearm 2.Additionally, the aid is provided with resilient means 38 which, in use,generate a moment of force between the first and second body relative tothe hinge (and hence relative to the rotation axis of the two bodies),such that the second body 32, hinging relative to the first body 30,presses against the palm of the hand 36 in a direction directed towardsthe upper side of the hand belonging to the palm (this direction isindicated in FIG. 2b with the vector D12).

[0032] The aid 13 in FIG. 3a comprises a first body 30 which is ofsubstantially tubular design and is provided with a channel-shapedmember 40 of a rigid material and a first elastically adjustable strap42 which is connected to the channel-shaped member 40. Thechannel-shaped member 40 is arranged to embrace, in use, at least a partof an upper side of the forearm 2, while the first strap 42 bridges anopen longitudinal side of the channel-shaped member, thereby passingover at least a part of an underside of the forearm. The first strap 42can be provided with a fastening mechanism comprising, for instance,Velcro tape or clasps.

[0033] The second body 32 of the aid 13 is arranged to embrace the partof the hand 10 situated between the index finger and the little finger.According to the embodiment of FIG. 3a, the second body 32 issubstantially tubular and made of a rigid material. The hand 10 ispreferably not completely covered, so that the hand is restricted aslittle as possible in its gripping function by the aid 13 secured to theforearm 2. Further, the resilient means are designed as a resilient body38. This resilient body 38 comprises a first and a second end betweenwhich a spring force increases when they are moved further away fromeach other. The resilient body 38 can be an elongate elastic material(such as an elastic). The first end of the resilient body 38 is attachedto the first body 30, at a position 44, which, in use, lies at an upperside of the forearm. The second end is connected with the second body 32at a position 46, which, in use, lies at an upper side of the hand. In afurther elaborated embodiment according to FIG. 3a, the first body 30 isprovided with a first side wall 48 and a second side wall 50 which aresituated opposite each other (see FIG. 3b). The second body 32 isprovided with a first side wall 49 and an opposite second side wall 51.The aid 13 here comprises a first hinge 34 and a second hinge 35 whichare situated opposite each other on either side of the wrist. The firsthinge 34 hingedly connects the first side wall 48 of the first body 30with the first side wall 49 of the second body 32 about a rotation axis(this rotation axis is substantially perpendicular to the plane of thedrawing of FIG. 3a). The second hinge 35 hingedly connects the secondside wall 50 of the first body 30 to the second side wall 51 of thesecond body about the rotation axis mentioned.

[0034] In FIG. 4, a first alternative embodiment of an aid according tothe invention is shown. In this embodiment of the aid 13, the first body30 is of a substantially tubular design and manufactured from a rigidmaterial. The tubular first body 30 is arranged to embrace a forearm.The second body 32 is arranged to embrace the part of the hand of theforearm situated between the index finger and the little finger, thissecond body 32 being of substantially tubular design and manufacturedfrom a rigid material. In a further elaborated embodiment accosting toFIG. 4, the first body 30 is provided with a first side wall 48 and asecond side wall 50, situated opposite each other. The second body 32 isprovided with a first side wall 49 and an opposite second side wall 51.The aid 13 here comprises a first hinge 52 and a second hinge which aresituated opposite each other on either side of the arm. The first hinge52 hingedly connects the first side wall 48 of the first body 30 to thefirst side wall 49 of the second body 32 about a rotation axis. Therotation axis is indicated in FIG. 4 with reference numeral 55. Thesecond hinge hingedly connects the second side wall 50 of the first body30 to the second side wall 51 of the second body 32 about the rotationaxis mentioned. The aid 13 further comprises resilient paeans which areprovided with a resilient body 38 having a first and second end betweenwhich a spring force increases when they are moved-further away fromeach other. The first end of the resilient body 38 is attached to thefirst body at a position 44 which, in use, lies at an upper side of theforearm, and the second end is connected to the second body at aposition 46 which, in use, lies at an upper side of the hand.

[0035] In FIG. 5, a second alternative embodiment of the aid 13according to the invention is given. Here, the first body 30 of the aid13 is of a substantially tubular design and is provided with achannel-shaped member 40 of a rigid material and a flexible strap 56.The channel-shaped member 40 is connected to the first flexible strap 56and is arranged to embrace, in use, at least a, part of an underside ofa forearm. The first strap 56 bridges an open, longitudinal side of thechannel-shaped member 40 and passes over at least a part of an upperside of the forearm. The second body is arranged to embrace the part ofthe hand situated between the index finger and the little finger, towhich send the second body is of a substantially tubular design.Further, the second body is provided with a pressure member 58 of arigid material and a flexible second strap 60 which is connected to thepressure member 58. The pressure member 58 is arranged to abut, in use,at least partly, against the palm of the hand, while the second strap 60passes over the back of the hand. Preferably, the first and second strapare provided with a fastening mechanism comprising, for instance, Velcrotape or clasps. In a further elaborated embodiment according to FIG. 5,the first body 30 is provided with a first side wall 48 and a secondside wall 50, situated opposite each other. The second body 32 isprovided, with a first side wall 49 and an opposite, second side wall51. The aid here comprises a first hinge 52 and a second hinge 53,situated opposite each other. The fist hinge 52 hingedly connects thefirst side wall 48 of the first body 30 to the first side wall 49 of thesecond body around a rotation axis. The second hinge 53 hingedlyconnects the second side wall 50 of the first body 30 to the second sidewall 51 of the second body 32 around the rotation axis 55. In thisembodiment, the first hinge 52 and the second hinge are each providedwith resilient means which press the first body 30 and the second body32 relative to each other about the rotation axis 55 to a predeterminedposition in which the first and second body include a predeterminedangle α. This angle α is in a plane perpendicular to the rotation axis55. In FIG. 5, this angle α is schematically indicated by means of twodotted lines. These dotted lines indicate the positions of the firstbody 30 and the second body 32 of the aid 13 relative to each other whenthe aid 13 is in the initial or rest position. (In FIG. 5, the aid 13 isnot represented in the position of rest. The position represented inFIG. 5 can be achieved from the position of rest by applying an externalmoment of force between the first body and the second body).

[0036] In FIGS. 6a and 6 b, a third alternative embodiment of an aidaccording to the invention is shown, in which parts corresponding to thepreceding figures are provided with the same reference numerals. In thedevice according to FIGS. 6a and 6 b, the first body 30 is provided witha first channel-shaped member 40. The channel-shaped member is furtherprovided with a first side wall 48 and a second side wall 50. In thefirst and second side wall 48, 50, slotted openings 60, 62 are provided.Through these openings, a strap 63 can be laced, such that it extendsover an upper side of a forearm of a user for securing the first body 30to the forearm. For closing the strap in a loop-shape, the ends of thestrap can, for instance, be provided with Velcro tape.

[0037] In this example, the second body 32 is likewise provided with asecond channel-shaped member 41. The second channel-shaped member 41 isprovided with two side walls 49, 51, situated opposite each other. Thesecond body also comprises a pressure member 58 arranged to lie, in use,at least partly against the palm of the hand. In particular, this partof the second channel-shaped member extends, in use, between a part ofthe inside of the hand situated between the index finger and the littlefinger. This part of the channel-shaped member lies against this part ofthe hand and presses against it. The aid further comprises a first andsecond hinge 52, 53, the first binge 52 hingedly connecting the firstside walls 48, 49 to each other and the second hinge 63 hingedlyconnecting the two side walls 50, 51 to each other. In this example, thefirst side walls 48, 49 and the second side walls 50, 51 are pivotallyconnected to each other around an imaginary rotation axis 55.

[0038] The first hinge 52 is provided with a first metal resilientbar-shaped member 52 having a first and second end 70, 72 which areconnected-to the first side wall 48 and the second side wall 49,respectively. The second hinge is likewise provided with a, in this casesecond, metal resilient liar-shaped member 53 having a first and secondend 70, 72, which are connected to the second side walls 50, 51,respectively. The first and second metal bar-shaped members 52, 53 alsoform the earlier-mentioned resilient means.

[0039] In the example, the first and second bar-shaped member 52, 5 aremanufactured from memory metal. In this example, the memory metalcomprises a memory alloy in austenitic condition.

[0040] When the aid is not in use and the resilient means 52, 53 arerelaxed, the aid is in a condition as shown its FIG. 6b. In use, the aidis in a condition according to FIG. 6a when the hand is extended aroundthe wrist joint in line with the forearm. The moment of force referredto is then exerted on the hand.

[0041] The memory metal has as a property that when, for instance,taking as a starting point the condition in FIG. 6a, the resilient means52, 53 are bent in the direction of rotation R as shown in FIG. 3a, or,conversely, are bent in a direction of rotation opposite to thedirection R as shown in FIG. 3a, the moment of force exerted on the palmof the hand will change little. The material chosen has the propertiesspecific for memory metal in austenitic form, i.e. large elasticdeformation is possible (8% or more, so-called superelasticity).Further, a very low modulus of stiffness is involved when the materialstress reaches the so-called plateau stress.

[0042] Starting from the condition in FIG. 6a, when the aid is worn by auser, the moment of force will only decrease slowly, that is, little,when the second body is moved in the direction R, as shown in FIG. 3arelative to the first body, or when the second body is moved relative tothe first body in a direction opposite to the direction R of FIG. 3a. Itfollows that a fairly constant flexiforce (moment of force) is exertedon the hand which is reasonably independent of the position, i.e. theposition the hand takes relative to the forearm.

[0043] Furthermore, lax particular with the above-mentioned choice ofmaterial, the first and second bar-shaped member can have a length of 40mm to 120 mm. Further, the first and the second bar-shaped member canhave a diameter of 0.5 to 2 mm.

[0044] The first body 30 can be manufactured from, for instance, asemi-rigid plastic material which has been conformed to the forearm ofthe patient by heating. The second body can also be manufactured from asemi-rigid plastic which has been conformed to the hand of the patientby heating.

[0045] In the example of FIG. 6a, mention is made, of a firstchannel-shaped member 44 provided with the flexible strap 63. Theflexible strap 63 and the channel-shaped member 40 together form atubular member which can embrace the forearm completely. In the presentpatent application, the term channel-shaped member therefore encompassesa first body of a tubular design. In particular, also the strap 63 canbe replaced with the same material as that from which the channel-shapedmember 40 is manufactured. In that case, a tube made in one piece fromplastic as shown in FIG. 4 is obtained. What holds true for the firstbody 30, also holds true, by analogy, for the second body 32, which,accordingly, can also be of tubular design and the term channel-shaped,in this context, encompasses a tubular shape.

[0046] It is also conceivable that the first body 30 has a tubulardesign, wherein, in the first body at its upper side, i.e. the sidewhich, in use, is on top of the forearm, a cut 80 is provided. Thisarrangement is schematically shown in FIG. 6b. Parts 82, 84 can then bebent away from each other to enlarge the cut 80 to position the firstbody 30 around the arm. The pressure point 6 shown in FIG. 1 is animaginary pressure point in this example, which is formed in combinationby symmetrical forces between the first body and the forearm. Suchvariants are all understood to fall within the scope of the invention.

[0047] The invention has been described on the basis of a few preferredembodiments, but, as will be evident to the skilled person, manyembodiments are possible which also fall within the scope of theinvention. It is possible, for instance, to design the aid in allpossible combinations of the above described embodiments of the firstand the second body of the aid. These embodiments can be realized indifferent sizes in a version for the left as well as for the right arm.Further, there are various alternatives with which the resilient meanscan be provided, it being possible, for instance, that the resilientmeans comprise a leaf spring (resilient means also encompass resilientmeans causing a rotation to extension, both through pull forces andpressure forces). The resilient means can be incorporated in the hinge.

1. An aid for relaxing the extensor musculature in the forearm, providedwith a first body, a second body and at least one hinge joint hingingthe first and second body together, wherein the first body is arrangedto be secured to a forearm while the second body extends from the hingeto a palm of the hand belonging to the forearm, the aid being furtherprovided with resilient means, which, in use, generate a moment of forcebetween the first and second body, such that the second body, hingingrelative to the first body, presses against the palm of the hand in adirection directed towards the upper side of the hand belonging to thepalm, characterized in that the resilient means are arranged such thatsaid moment of force is at least exerted on the hand when the hand isextended in line with the forearm.
 2. An aid according to claim 1,characterized in that the first body is provided with a firstchannel-shaped member of a rigid material.
 3. An aid according to claim2, characterized in that the first channel-shaped member is arranged toembrace, in use, at least a part of an underside of the forearm.
 4. Anaid according to claim 1, 2 or 3, characterized in that the second bodyis provided with a second channel-shaped member of a rigid material. 5.An aid according to claim 4, characterized in that the secondchannel-shaped member is arranged to abut, in use, against at least apart of an inside of the hand situated between the index finger and thelittle finger.
 6. An aid according to claim 2 or 3 and according toclaim 3 or 4, characterized in that the first channel-shaped member isprovided with a first and second side wall situated opposite each other,the second channel-shaped member is provided with a first and secondside wall situated opposite each other, and the at least one hingecomprises a first and second hinge, the first hinge hinging the firstside wail together about a rotation axis and the second hinge hingingthe second side walls together about the rotation axis.
 7. An aidaccording to claim 6, characterized in that the first hinge is providedwith a first metal resilient bar-shaped member having a first and secondend which se connected to the first side walls of the first and secondchannel-shaped member, respectively, and the second hinge is providedwith a second metal resilient bar-shaped member having a first andsecond end connected with the second side walls of the first and secondchannel-shaped member, respectively, wherein the first and secondbar-shaped element form the resilient means.
 8. An aid according to anyone of the preceding claims, characterized in that the resilient meansare provided with a memory metal, such that the moment of force exertedon the palm of the hand is a substantially constant flexiforce,independently of the position the hand takes around the twist jointrelative to the forearm.
 9. An aid according to claims 7 and 8,characterized in that the first and second bar-shaped member aremanufactured from the memory metal.
 10. An aid according to claim 8 or9, characterized in that the memory metal comprises a memory alloy inaustenitic condition.
 11. An aid according to claim 7, 9 or 10,characterized in that the first and second bar-shaped member have alength of 40 mm to 120 mm.
 12. An aid according to claim 7, 9, 10 or 11,characterized in that the first and second bar-shaped member have adiameter of 0.5 mm to 2 mm.
 13. An aid according to claim 1,characterized in that the first body is of substantially tubular designand is provided with a channel-shaped member of a rigid material and afirst elastically adjustable strap which is connected to thechannel-shaped member, wherein the channel-shaped member is arranged toembrace, in use, at least a part of an upper side of the forearm whilethe first strap bridges an open longitudinal side of the channel-shapedmember, thereby passing over at least apart of an underside of theforearm.
 14. An aid according to claim 1, characterized in that thefirst body is of substantially tubular design and is provided with achannel-shaped member of a rigid material and a first elasticallyadjustable strap which is connected to the channel-shaped member, wherethe channel-shaped member is arranged to embrace, in use, at least apart of an underside of the forearm while the fist strap bridges an openlongitudinal side of the channel-shaped member, thereby passing over atleast a part of an upper side of the forearm.
 15. An aid according toclaim 13 or 14, characterized in that the first strap is provided with afastening mechanism comprising, for instance, Velcro tape or clasps. 16.An aid according to claim 1, characterized in that the first body has asubstantially tubular design and is made of a rigid material, thetubular first body being arranged to embrace the forearm.
 17. An aidaccording to any one of the preceding claims 13-16, characterized inthat the second body is arranged to embrace the part of the handsituated between the index finger and the little finger.
 18. An aidaccording to claim 17, characterized in that the second body has asubstantially tubular design and is provided with a pressure element ofa rigid material and a second elastically adjustable strap which isconnected to the pressure element, the pressure element being arrangedto abut, in use, at least partly against the palm of the hand while thesecond strap passes over the back of the hand.
 19. An aid according toclaim 18, characterized in that the second strap is provided with afastening mechanism comprising for instance Velcro tape or clasps. 20.An aid according to claim 17, characterized in that the second body hasa substantially tubular design and is manufactured from a rigidmaterial.
 21. An aid according to any one of claims 13-16 and any one ofclaims 17-20, characterized in that the resilient means are providedwith a resilient body having a first and a second end between which aspring force increases when these are moved further away from eachother, wherein a first end is connected to the first body at a positionwhich, in use, lies at an upper side of the forearm and wherein thesecond end is connected to the second body at a position which, in use,lies at an upper side of the hand.
 22. An aid according to claim 21 orany one of the preceding claims 13-16 and any one of claims 17-21,characterized in that the first body is provided with a first and secondside wall situated opposite each other, the second body is provided witha first and second side wall situated opposite each other and the atfirst one hinge comprises a first and second hinge, the first hingehinging the first side walls together about a rotation as and the secondhinge hinging the second side walls together about the rotation axis.23. An aid according to claim 22, characterized in that the first andsecond hinge each axe provided with the resilient means which press thefirst and second body relative to each other about the rotation axis toa predetermined position in which the first and second body include apredetermined angle, which angle is in a plane perpendicular to therotation axis.
 24. An aid according to any one of claims 13-16 and anyone of claims 17-20, characterized in that the resilient means areprovided with a (leaf) spring having a first and a second end, wherein afirst end is connected to the first body at a position which, in use,lies at an upper side of the forearm and wherein the second end isconnected to the second body at a position which, in use, lies at anupper side of the hand.
 25. An aid according to claim 24, characterizedin that the a (leaf) spring is provided with a memory metal, such thatthe moment of force exerted on the palm of the had is a substantiallyconstant flexiforce, independently of the position the hand takes aroundthe twist joint relative to the forearm.
 26. An aid for relaxing theextensor musculature in the forearm, provided with a first body, asecond body and at least one hinge joint hinging the first and secondbody together, wherein the first body is arranged to be secured to aforearm while the second body extends from the hinge to a palm of thehand belonging to the forearm, the aid being further provided withresilient means, which, in use, generate a moment of force between thefirst and second body, such that the second body, hinging relative tothe first body, presses against the palm of the hand in a directiondirected towards the upper side of the hand belonging to the palm,characterized in that the resilient means are provided with a memorymetal, such that the moment of force exerted on the palm of the hand isa substantially constant flexiforce, independently of the position thehand takes around the twist joint relative to the forearm.
 27. A methodfor relaxing the extensor musculature through the principle of theflexor-extensor antagonism, wherein, through the application of forcesto at least three pressure points, on a forearm, the wrist of theforearm and the palm of the hand of the forearm, respectively, a momentof force is applied to the palm of the hand, such that the flexormusculature (flexors) in the forearm must be flexed, so that, as aresult of the antagonism between the flexor musculature and the extensormusculature in the fore arm, the extensor musculature is relaxed.